I do this too and it helps sometimes! I think it might be worth a try. Remind yourself that even though it feels very real, it's over and he's not here. Say it out loud if you have to.

When I have flashbacks/panic attacks I try to focus on being present in the moment. Breathing slowly, deeply, and deliberately helps with this (and it will get your heart rate down, which should help you feel a little calmer and relaxed). Another thing you might try is focusing on how your body is feeling right then in the present; it could help tear you away from reliving what your body felt during the awful experience. You could do that by doing something nice for yourself: put on lotion, brush your hair, whatever you think feels good, and really focus on the pleasant sensations it creates. Make your actions as deliberate as possible and try to get yourself to concentrate fully on what you are doing.

Thank you for sharing with us and posting here. That's a brave thing to do. Your words are important and valuable-YOU are important and valuable-and we're here to listen.